In recent years, the number of IoT (Internet of Things) devices connected to a LAN (Local Area Network) is increasing. A user can log in to the IoT device and use various functions of the IoT device, by inputting an ID or a password to a predetermined terminal.
When the user logs in to the IoT device, a problem arises in that the IoT device which the user does not intend to use is used by an unauthorized access of another user.
As a system for preventing such unauthorized access, for example, in a case where action plan information is prepared in advance and location information of a monitoring target device does not match with the action plan information, it is disclosed that the device is set to a locked state so that the unauthorized user cannot use the target device even after a password is leaked.